diff --git a/apps/backend/src/lib/pixiv.ts b/apps/backend/src/lib/pixiv.ts
index b0b4b78..d300da5 100644
--- a/apps/backend/src/lib/pixiv.ts
+++ b/apps/backend/src/lib/pixiv.ts
@@ -1,148 +1,44 @@
 import { MediaUpload } from "@/models/media";
 
-type PixivTag = {
-    tag?: unknown;
-    translation?: { en?: unknown } | null;
-};
+function fetchPixivData(url: string): Promise<any> {
+    // https://www.pixiv.net/artworks/143552616
+    const match = url.match(/\/artworks\/(\d+)/);
+    if (!match) {
+        throw new Error("Invalid Pixiv URL");
+    }
+    const artworkId = match[1];
 
-type PixivIllustBody = {
-    illustId?: unknown;
-    id?: unknown;
-    illustTitle?: unknown;
-    title?: unknown;
-    illustComment?: unknown;
-    description?: unknown;
-    urls?: Record<string, unknown>;
-    tags?: { tags?: PixivTag[] } | PixivTag[] | string[];
-    userId?: unknown;
-    userName?: unknown;
-    createDate?: unknown;
-    uploadDate?: unknown;
-    pageCount?: unknown;
-    xRestrict?: unknown;
-    url?: unknown;
-};
 
-type PixivAjaxResponse<T> = {
-    error?: boolean;
-    message?: string;
-    body?: T;
-};
+    return fetch(`https://www.phixiv.net/api/info?id=${artworkId}&language=ko`)
+        .then((response) => {
+            if (!response.ok) {
+                throw new Error(`Failed to fetch Pixiv data: ${response.status} ${response.statusText}`);
+            }
+            return response.json();
+        })
+        .then((data) => {
+            // if #R-18 in tags, throw error
+            if (data.tags && data.tags.some((tag: string) => tag.includes("R-18"))) {
+                throw new Error("Pixiv artwork is marked as R-18");
+            }
 
-type PixivPage = {
-    urls?: Record<string, unknown>;
-};
+            return data;
+        })
+        .then((data) => {
+            if (data.error) {
+                throw new Error(`Pixiv API error: ${data.message}`);
+            }
+            return data;
+        });
+}
 
-function extractArtworkId(url: string): string {
-    const match = url.match(/(?:\/artworks\/|\/ajax\/illust\/)(\d+)/);
+async function checkPixivData(url: string, selected: Array<boolean>) {
+    const match = url.match(/\/artworks\/(\d+)/);
     if (!match) {
         throw new Error("Invalid Pixiv URL");
     }
 
-    return match[1];
-}
-
-function pixivAjaxUrl(path: string): string {
-    return `https://www.pixiv.net/ajax/illust/${path}`;
-}
-
-function getPreferredImageUrl(urls: Record<string, unknown> | undefined): string | null {
-    if (!urls) return null;
-
-    for (const key of ["original", "regular", "small", "thumb"]) {
-        const value = urls[key];
-        if (typeof value === "string" && value.length > 0) return value;
-    }
-
-    return null;
-}
-
-function normalizeTags(tags: PixivIllustBody["tags"]): string[] {
-    const tagList = Array.isArray(tags)
-        ? tags
-        : tags && typeof tags === "object" && "tags" in tags
-            ? tags.tags
-            : [];
-    if (!Array.isArray(tagList)) return [];
-
-    return tagList
-        .map((entry) => {
-            if (typeof entry === "string") return entry;
-            if (typeof entry.tag === "string") return entry.tag;
-            return null;
-        })
-        .filter((tag): tag is string => tag !== null && tag.length > 0);
-}
-
-function makePixivRequest(url: string) {
-    return fetch(url, {
-        headers: {
-            "Accept": "application/json",
-            "Referer": "https://www.pixiv.net/",
-            "User-Agent": "Mozilla/5.0 (compatible; akiyama.mizuki.guru/1.0)",
-        },
-    });
-}
-
-async function readPixivJson<T>(url: string): Promise<T> {
-    const response = await makePixivRequest(url);
-    if (!response.ok) {
-        throw new Error(`Failed to fetch Pixiv data: ${response.status} ${response.statusText}`);
-    }
-
-    const data = (await response.json()) as PixivAjaxResponse<T>;
-    if (data.error) {
-        throw new Error(`Pixiv API error: ${data.message || "unknown error"}`);
-    }
-    if (data.body === undefined) {
-        throw new Error("Pixiv API response did not include a body");
-    }
-
-    return data.body;
-}
-
-async function fetchPixivData(url: string): Promise<any> {
-    const artworkId = extractArtworkId(url);
-    const body = await readPixivJson<PixivIllustBody>(pixivAjaxUrl(`${artworkId}?lang=ko`));
-    const pageCount = typeof body.pageCount === "number" ? body.pageCount : 1;
-    const tags = normalizeTags(body.tags);
-
-    if (tags.some((tag) => tag.includes("R-18"))) {
-        throw new Error("Pixiv artwork is marked as R-18");
-    }
-    if (body.xRestrict === 1 || body.xRestrict === 2) {
-        throw new Error("Pixiv artwork is restricted");
-    }
-
-    let imageUrls: string[] = [];
-    if (pageCount > 1) {
-        const pages = await readPixivJson<PixivPage[]>(pixivAjaxUrl(`${artworkId}/pages?lang=ko`));
-        imageUrls = pages
-            .map((page) => getPreferredImageUrl(page.urls))
-            .filter((imageUrl): imageUrl is string => imageUrl !== null);
-    } else {
-        const imageUrl = getPreferredImageUrl(body.urls);
-        if (imageUrl) imageUrls = [imageUrl];
-    }
-
-    return {
-        url: `https://www.pixiv.net/artworks/${artworkId}`,
-        illust_id: String(body.illustId || body.id || artworkId),
-        title: String(body.illustTitle || body.title || "Pixiv Artwork"),
-        description: String(body.illustComment || body.description || ""),
-        author_id: String(body.userId || "unknown"),
-        author_name: String(body.userName || "unknown"),
-        create_date: typeof body.createDate === "string" ? body.createDate : body.uploadDate,
-        tags,
-        image_proxy_urls: imageUrls,
-        image_urls: imageUrls,
-        page_count: pageCount,
-        raw: body,
-    };
-}
-
-async function checkPixivData(url: string, selected: Array<boolean>) {
-    const artworkId = extractArtworkId(url);
+    const artworkId = match[1];
     const selectedIndices = selected
         .map((isSelected, index) => (isSelected ? index : -1))
         .filter((index) => index >= 0);
@@ -159,4 +55,4 @@ async function checkPixivData(url: string, selected: Array<boolean>) {
     return existing !== null;
 }
 
-export { checkPixivData, fetchPixivData };
+export { checkPixivData, fetchPixivData };
\ No newline at end of file
diff --git a/apps/backend/src/lib/s3.ts b/apps/backend/src/lib/s3.ts
index c98afd3..16e368f 100644
--- a/apps/backend/src/lib/s3.ts
+++ b/apps/backend/src/lib/s3.ts
@@ -31,16 +31,7 @@ async function uploadToS3(fileName: string, mediaUrl: string, maxRetry = 3) {
 
   for (let attempt = 1; attempt <= maxRetry; attempt++) {
     try {
-      const parsedUrl = new URL(mediaUrl);
-      const isPixivImage = parsedUrl.hostname === "i.pximg.net";
-      const response = await fetch(mediaUrl, {
-        headers: isPixivImage
-          ? {
-            "Referer": "https://www.pixiv.net/",
-            "User-Agent": "Mozilla/5.0 (compatible; akiyama.mizuki.guru/1.0)",
-          }
-          : undefined,
-      });
+      const response = await fetch(mediaUrl);
       if (!response.ok) {
         throw new Error(`Fetch failed: ${response.status}`);
       }
@@ -83,4 +74,4 @@ async function writeToS3(fileName: string, data: ArrayBuffer | Blob, contentType
   });
 }
 
-export { makeS3FileName, uploadToS3, writeToS3, client as s3Client };
+export { makeS3FileName, uploadToS3, writeToS3, client as s3Client };
\ No newline at end of file
diff --git a/apps/backend/src/routes/proxy.ts b/apps/backend/src/routes/proxy.ts
index 0a01901..bd16510 100644
--- a/apps/backend/src/routes/proxy.ts
+++ b/apps/backend/src/routes/proxy.ts
@@ -5,7 +5,6 @@ const ALLOWED_HOSTS = [
     "video.twimg.com",
     "ton.twimg.com",
     "abs.twimg.com",
-    "i.pximg.net",
 ];
 
 export default new Elysia({ prefix: "/proxy" })
@@ -26,7 +25,7 @@ export default new Elysia({ prefix: "/proxy" })
         const response = await fetch(targetUrl, {
             headers: {
                 "User-Agent": "Mozilla/5.0 (compatible; akiyama.mizuki.guru/1.0)",
-                "Referer": parsed.hostname === "i.pximg.net" ? "https://www.pixiv.net/" : "https://twitter.com/",
+                "Referer": "https://twitter.com/",
             },
         });
 
diff --git a/apps/frontend/src/app/add/page.tsx b/apps/frontend/src/app/add/page.tsx
index 978ab50..77617e4 100644
--- a/apps/frontend/src/app/add/page.tsx
+++ b/apps/frontend/src/app/add/page.tsx
@@ -250,7 +250,7 @@ export default function AddPage() {
             const data = (await response.json()) as PixivApiResponse;
             const items = (data.image_proxy_urls ?? [])
                 .filter((imageUrl): imageUrl is string => typeof imageUrl === "string" && imageUrl.length > 0)
-                .map((imageUrl) => ({ url: proxyMediaUrl(imageUrl) }));
+                .map((imageUrl) => ({ url: imageUrl }));
 
             if (items.length === 0) throw new Error("이미지를 찾지 못했습니다.");
 
diff --git a/apps/frontend/src/lib/media.ts b/apps/frontend/src/lib/media.ts
index 11abad8..56f43a6 100644
--- a/apps/frontend/src/lib/media.ts
+++ b/apps/frontend/src/lib/media.ts
@@ -3,7 +3,6 @@ const PROXIED_HOSTS = [
   "video.twimg.com",
   "ton.twimg.com",
   "abs.twimg.com",
-  "i.pximg.net",
 ];
 
 export function proxyMediaUrl(url: string | undefined | null): string {
diff --git a/bun.lock b/bun.lock
index 51a1899..2f1921f 100644
--- a/bun.lock
+++ b/bun.lock
@@ -9,11 +9,11 @@
       "name": "elysia",
       "version": "1.0.50",
       "dependencies": {
-        "@aws-sdk/client-s3": "^3.1075.0",
+        "@aws-sdk/client-s3": "^3.1053.0",
         "@elysiajs/jwt": "^1.4.2",
         "@elysiajs/openapi": "^1.4.15",
         "elysia": "latest",
-        "mongoose": "^9.7.2",
+        "mongoose": "^9.6.2",
         "ulid": "^3.0.2",
       },
       "devDependencies": {